A bidder is someone who offers to pay a certain amount of money for something that is being sold. If you sell something to the highest bidder, you sell it to the person who offers the most money for it.
双语例句
例：
The sale will be made to the highest bidder subject to a reserve price being attained.
在保证底价的条件下，出售给出价最高者。
2.?[C 可数名词] 努力争取的人
A bidder for something is someone who is trying to obtain it or do it.
双语例句
例：
Vodafone is among successful bidders for two licences to develop mobile phone systems in Greece.